Polymorphism of feldspars above 10 GPa

Abstract

Feldspars are stable at pressures up to 3 GPa along the mantle geotherm, but they can persist metastably at higher pressures at colder conditions. Here, above 10 GPa the authors find new high-pressure polymorphs of feldspars that could persist at depths corresponding to the Earth’s upper mantle, potentially influencing the dynamics and fate of cold subducting slabs.